Age-Related Features of the Early Period of Liver Regeneration after Partial Hepatectomy in Rats

Regenerative processes in the liver were studied in 3-month-old (young) and 9-month-old (aged) male Wistar rats on day 1 after 30 and 70% hepatectomy. Regardless of the resected liver volume, shifts in the biochemical parameters of the serum in aged rats were more pronounced than in young animals. After 30% hepatectomy, no age differences in the rate of hepatic regeneration were found, while after 70% liver resection this parameter was higher in young rats. Hepatectomy in young rats led to recruitment of MSC, hepatocyte precursors, endothelial and epithelial progenitor cells into the liver parenchyma and increased fluidity of the plasma and mitochondrial membranes of hepatocytes. In aged rats, the recruitment of MSC, hepatocyte precursors, and endothelial progenitor cells into the injured liver was impaired and the rigidity of the mitochondrial membranes of hepatocytes increased.

Expression of Genes and Proteins of the Sarcoplasmic Reticulum Са2+-Transport Systems in Cardiomyocytes in Concomitant Coronary Heart Disease and Type 2 Diabetes Mellitus

We compared the expression of Са²⁺-ATPase (SERCA2a), calsequestrin (CASQ2), ryanodine receptors (RyR2) proteins and their genes (ATP2A2, CASQ2, and RYR2) in coronary heart disease (CHD) patients with and without comorbid type 2 diabetes mellitus. All studies were performed on the right atrial appendages resected during coronary bypass surgeries. Expression of SERCA2a and RyR2 proteins and their ATP2A2 (p=0.046) and RYR2 genes in comorbid pathology was significantly (p=0.042) higher (by 1.2 and 2 times; p=0.025). The expression of CASQ2 protein and its gene did not differ significantly between the groups (p=0.82 and p=0.066, respectively). It was concluded that the expression of SERCA2a and RyR2 proteins and their genes (but not CASQ2 and its gene) is elevated in CHD associated with type 2 diabetes mellitus. Expression of the studied proteins correlated with the expression of their genes. Increased expression of CASQ2 protein and its gene can probably prevent imbalance of the Ca²⁺-transporting systems in cardiomyocytes and contractile dysfunction of the myocardium, even in CHD associated with type 2 diabetes mellitus.

Age-Related Features of the Viscosity of Plasma and Mitochondrial Membranes of Hepatocytes in Liver Cirrhosis

The viscosity of plasma and mitochondrial membranes of hepatocytes was studied in young (3-month-old) and old (9-month-old) male Wistar rats. It was shown that viscosity of hepatocyte plasma and mitochondrial membranes in young rats under optimal vital functions in the area of protein-lipid membrane contacts was significantly lower than in old rats. No age-related differences in the viscosity of lipid-lipid membrane contacts and in the polarity of protein-lipid contacts and lipid layers were found. Liver cirrhosis induced by carbon tetrachloride and ethanol administration was associated with increased fluidity of the plasma and mitochondrial membranes of hepatocytes in rats of both age groups. The decrease in membrane viscosity in young rats occurred due to a decrease of the viscosity in the area of protein-lipid and lipid-lipid contacts, while in old rats in the area of protein-lipid contacts. Carbon tetrachloride and ethanol did not affect the polarity of lipid contacts and lipid layers.

Experimental Cardiomyogenesis Under Conditions of Administration of Different Doses of the Allogeneic Biomaterial

We studied the effect of different concentrations of the allogeneic biotransplant on myocardial recovery. In Wistar rats, coronary artery was ligated and intramyocardial injection of 12 or 24 mg Alloplant biomaterial suspension was performed. Histological analysis was conducted on paraffin sections stained by Mallory. The index of the scar area was measured on preparations of transverse sections of the hearts. Allogeneic biomaterial produced cardioprotective and regenerative effect in the myocardium damaged by ischemia. After administration of Alloplant in a dose of 12 mg, the index of scar area decreased by 2.74 times; after doubling the Alloplant dose (24 mg), the index of scar area decreased by 26 times.

Comparative study of changes in energy metabolism in rat cardiomyocytes in postinfarction cardiosclerosis and diabetes mellitus

Cardiomyocyte energy metabolism in experimental unfolding postinfarction cardiosclerosis and diabetes mellitus was studied. Postinfarction cardiosclerosis formed 6 weeks after coronary artery occlusion. Diabetes mellitus was induced by intraperitoneal injection of streptozotocin (60 mg/kg). The rate of oxygen consumption in postinfarction cardiosclerosis and diabetes increased by 3.4 and 4.2 times, respectively. Stimulation of mitochondrial respiration (ATP, palmitic acid) significantly increased oxygen consumption in animals with postinfarction cardiosclerosis and significantly reduced this process in diabetes. The content of LDH and SDH in the myocardium of animals with diabetes and postinfarction cardiosclerosis was significantly below the control. Hence, the development of postinfarction cardiosclerosis and diabetes mellitus were characterized by reduced generation of ATP in anaerobic and aerobic pathways and oxidative phosphorylation in cardiomyocytes.

Expression of Ca(2+)-ATPase in sarcoplasmic reticulum in rat cardiomyocytes during experimental postinfarction cardiosclerosis and diabetes mellitus

We studied the expression of Ca(2+)-ATPase in sarcoplasmic reticulum of rat cardiomyocytes during isolated and combined development of postinfarction cardiosclerosis and diabetes mellitus. Postinfarction cardiosclerosis was formed within 6 weeks after coronary artery occlusion. Diabetes mellitus developed within 6 weeks after intraperitoneal injection of streptozotocin (60 mg/kg). Ca(2+)-ATPase in homogenate of rat myocardium was assayed by immunoblotting. Ischemic and diabetic remodeling of the myocardium was associated with reduced expression of Ca(2+)-ATPase in the sarcoplasmic reticulum. Combined pathology was characterized by minimum decrease in the level of this protein. It was concluded that induction of diabetes mellitus at the early stage of postinfarction cardiosclerosis triggered adaptive mechanisms that prevent the decrease in Ca(2+)-ATPase level in the sarcoplasmic reticulum of cardiomyocytes.

[Microviscosity of erythrocyte membranes in chronic coronary insufficiency in patients of middle and older age groups]

We examined the ratios microviscosity in the area of integral and annularly lipid membranes of erythrocytes of peripheral blood in patients of 35-50 and 60-75 years with chronic ischemic heart disease, as well as age-matched healthy controls. In healthy donors coefficients microviscosity in the area of integral and annularly lipids proved to be significantly higher in the older age group (60-75 years). In CHD, regardless of the age of the patients, erythrocyte membranes can be characterized as raising and lowering the parameters microviscosity of lipid-lipid interactions. In the protein-lipid contacts for patients aged 35-50 years an increase is typical, while for patients of 60-75 years, on the contrary, a decrease of the coefficient of microviscosity. It is concluded that the values of the microviscosity of erythrocyte membranes in patients of different age groups in the development of chronic ischemic heart disease, reflect both the implementation of the general mechanisms of adaptive changes of cell membranes, and the specifics of an individual, determined by their lipid and protein composition.

[Auricular vagal stimulation in the treatment of patients with left ventricular dysfunction]

We assessed effect of enhancement of parasympathetic activity by indirect vagal stimulation via sensitive n. vagus-r. auricularis terminals on dynamics of clinical conditions, ejection fraction and global longitudinal left ventricle deformation in patients with chronic cardiac insufficiency (CCI). This comparative placebo-controlled parallel study 3 months in duration included 70 patients with chronic coronary heart disease, signs of IIl-IV FC CCI, and sinus rhythm. Auricular electric vagal stimulation (AEVS) was performed using a device for electric stimulation of sensitive vagus terminals (patent No 2327492 of 27.06.2008). The complex of clinical and instrumental studies included 6 min walk test, echocardiography, and speckle tracking imaging before, immediately and 3 months after AEVS. A course of AEVS improved clinical conditions in 58 (92.06%) of the 63 patients due to one-grade or greater decrease of CCI FC and increase of the walking distance. This effect persisted till month 3. It was absent in 5 (8.33%) patients. Improvement of clinical conditions with the decrease of CCI FC was accompanied by increase of left ventricular ejection fraction due to diminished end-systolic volume. The ejection fraction did not change in 4 patients with HR over 80/min. All patients with lowered HR after AEVS showed improved LV contractility in the longitudinal direction.

[Noninvasive assessment of functional competence of the radial artery as a possible vascular graft for coronary artery bypass grafting]

Described herein is a variant of surgical treatment of a patient presenting with type A aortic dissection extending to the brachiocephalic branches accompanied by thrombosis of the false channel of the latter. In the rare cases in dissection and thrombosis of the brachiocephalic branches for adequate protection of the body (systemic protection) it is necessary to use bidirectional arterial perfusion under the conditions of moderate hyperthermia: through a preliminarily sewn into the carotid artery prosthesis - perfusion of the brain, through cannulated aortic arch or femoral artery - body perfusion.

[Influence of the long-term administration of torasemide on morphometric characteristics of cardiac muscle under conditions of developed experimental postinfarction cardiosclerosis]

The possible antifibrotic effect of torasemide used for the treatment of model chronic heart failure (CHF) has been studied in rats aged 12 months with developed postinfarction cardiosclerosis (PICS). The antifibrotic effect was evaluated of the course of torasemide administration in a daily dose of 0.13 mg/kg. A comparative analysis showed that torasemide did not affect the state of connective tissues in cardiac muscles of both intact rats and those with PICS. It was concluded that manifestations of the antifibrotic effect of torasemide can be related to the nosological form of CHF.

[Manifestations of polymorphism of β1-adrenoreceptors in patients with newly diagnosed cardiac rhythm disorders]

Individual peculiarities of the receptor apparatus of cardiomyocytes may determine pathological features of heart activity and susceptibility to pharmaceuticals. The possible role of beta-adrenoreceptor polymorphism in the development of cardiac rhythm disturbances is assessed by PCR. Special attention is given to A145G polymorphism of the ADRB1 gene in 127 patients with primary cardiac rhythm disorders. It was shown that AJ45G polymorphism (Ser49Gly) at DNA sites encoding for the amino acid sequence of beta-1 adrenoreceptors can influence the development of sex-specific cardiac rhythm disorders.

[Resistance to clopidogrel and polymorphism of P2RY12 and GPIIIA genes in patients with chronic coronary heart disease]

We studied the association between clopidogrel resistance, H1/NH2 polymorphism of the P2RY12 gene and T156C polymorphism of the GpIIIa gene in residents of Western Siberia suffering chronic CHD. It was shown that the occurrence of H1 and H2 haplotypes of the P2RY12 gene and 1565T and 1565C alleles of the GpIIIa gene was similar to that reported for European populations. Patients showing variable platelet response to the inhibitory action of clopidogrel were not significantly different in terms of P2RY12 and GpIIIa genotype distribution. To conclude, the study revealed no association between the risk of clopidogrel resistance and the presence of polymorphic variants of platelet receptor genes P2RY12 and GpIIIa.

Radiofrequency ablation as a possible method for preparing pathologically altered myocardium for intramyocardial cell transplantation

We studied the effects of radiofrequency ablation on the results of intramyocardial transplantation of bone marrow NSC into the myocardium of rats with postinfarction cardiosclerosis. It was shown that exposure of the pathologically changed myocardium to radiofrequency radiation led to destruction of formed connective tissue. Transplantation of MSC into sites exposed to radiofrequency radiation promoted the development of regenerative processes (abundant infiltration with mononuclear cells, presence of granulation tissue, and numerous newly formed blood vessels). We concluded that preliminary radiofrequency irradiation of the myocardial areas promotes realization of the regenerative potential of cell transplantation.

Economical technology of creation of cell-free matrix of animal and human arterial vessels

We present a technology of creation of blood vessel connective tissue framework by 2-3-h vessel perfusion with detergents. The technology ensures effective removal of vascular cells without damaging collagen and elastic fibers. The connective tissue frameworks prepared by this method can the used for restoring blood flow in various vascular pathologies. The presented approach attenuates the damaging effect of treatment on the vascular framework due to maximum simplification and shortening of the duration of treatment and is universal for human and animal vessels.

[The experience of the application of ascorbinic acid as antioxidant after coronary artery surgery with use of cardiopulmonary bypass]

We have studied the role of oxidant stress in development of rhythm disturbances in early postoperative period after coronary artery bypass grafting and possibilities of their prevention with preparations of ascorbinic acid. It was shown that the use of β-adrenoblockers allows to prevent arrhythmia on first day after operation only in 80% of cases. Patients with developed disturbances of cardiac rhythm were characterized by high parameters of lipid peroxidation (LPO) and substantial changes of activity of antioxidant enzyme catalase. Administration of ascorbinic acid at the stage of preparation of patients to surgery and in first 24 hours after operation allowed to effectively prevent development of oxidative stress and disturbances of cardiac rhythm. A conclusion was made that inclusion of ascorbinic acid in drug therapy of patients with ischemic heart disease could be recommended for prevention of arrhythmia in postoperative period.

[D allele of the angiotensin converting enzyme gene is a putative risk factor of restenosis after coronary stenting in patients with coronary heart disease]

We undertook a comparative analysis of allele frequency distribution and I/D polymorphism of the angiotensin converting enzyme (ACE) gene in patients with coronary heart disease (CHD) undergoing coronary stenting with and without signs of restenosis. There were no significant difference between the groups in the genotype frequency distribution of I/D polymorphism of the CAE gene (p = 0.061). The occurrence of D allele in the patients with restenosis was higher than that of I allele (chi-square test 4.117, p = 0.042). Relative risk for the carriers of D and I alleles was 0.35 and 2.83 respectively. It is concluded that the presence of D allele of I/D polymorphism of the CAE gene in patients with chronic CHD may be a risk factor of restenosis of stented coronary arteries.

[Consistence of the radial artery as a conduit used in aortocoronary bypass surgery, a possibility of preventing shunt spasm]

AIM

To develop a new procedure to evaluate the functional consistence of the radial artery (RA) as a conduit used in aortocoronary bypass surgery (ACBS), to verify the prognostic value of the changed diameter of RA, and to prevent its spasm.

SUBJECTS AND METHODS

The study enrolled 34 patients aged 59.4 +/- 8.6 years with coronary artery stenoses, who underwent ACBS using a RA conduit. While preparing them for surgery, endothelium-dependent vasodilation (EDVD) of RA, i.e. the magnitude of a change in its diameter (deltaD) was assessed; RA tone and nitric oxide (NO) concentrations were estimated during surgery; RA EDVD was re-estimated in 12 lercanidipine-treated patients with deltaD < 8%.

RESULTS

The patients were primarily divided into 2 groups: 1) deltaD > or = 8% (RA spasm intra- and postoperatively); 2) EDVD deltaD < 8% (RA spasm). Significant differences between Groups 1 and 2 were intraoperatively recorded in vascular wall tone (U = 1.0; Z = -2.3; p = 0.02) and NO concentrations (p = 0.0); a relationship was found between these parameters. After lercanidipine treatment, the degree of deltaD = 4.36 +/- 1.89% increased to 11.32 +/- 2.22% (p = 0.0) and RA tone dropped from -1.68 to -3.9 mm in Group 2a with the baseline decreased vasodilating activity of RA.

CONCLUSION

Ultrasound assessment of the vasodilating activity of RA provides adequate evidence about its arterial wall tone during surgery. deltaD < 8% is prognostically unfavorable and serves as a contraindication to the use of RA as a conduit during ACBS. The administration of lercanidipine allows effective correction of the dilatory capacities of an arterial conduit.

[Age-related features of microviscosity of erythrocyte membranes in experimental cardiosclerosis]

The age-related changes in the coefficient of microviscosity and polarity in the area of lipid-lipid and protein-lipid contacts of erythrocyte membranes in 4 months old (group I, n = 20) and 12 months old (group II, n = 20) rats by the method of lateral diffusion of the pyrene probe were investigated. Each age group consisted of 10 intact animals and animals after postinfarction cardiac remodeling (PICS). An increase of microviscosity and polarity of the annular and total lipids of erythrocyte membranes in 12-month animals was found. When modeling PICS in 4-month animals is pronounced increase the polarity and microviscosity of erythrocyte membranes in the annular and total lipids. The 12-month animals after PICS demonstrate a decrease of microviscosity in a lipid bilayer, and its increase in the area of annular lipids for consistently high-polarity lipids.

Cell-free collagen-based scaffolds used for making blood vessels in cardiovascular surgery

The present article deals with the technology of obtaining decellularized cell-free collagen-based scaffolds from arterial vessels and surgical assessment of the possibility of experimentally implanting them into the blood system of laboratory animals for experimental purposes. The study was performed on arterial vessels (n=60) and fragments of the human internal thoracic artery (n=20). Described herein is a method of obtaining a connective-tissue matrix of a blood vessel by means of vessel's perfusion for 2-3 hours with detergent solutions. Cell-free collagen-based conduits were implanted to a total of ten dogs. After the operation, the blood flow remained functional. The anastomoses established turned out to be leak-proof and the acellular vessels were able to withstand the haemodynamic load of the arterial blood flow.

[Inotropic reaction of myocardium rats with postinfarction and diabetic remodeling on extrasistolic influences]

Studied inotropic reaction papillary muscles of rats with postinfarction and diabetic remodeling on extrasistolic influences. It was found, that excitability of myocardium rats raises at a diabetes induced streptozotocin. Postextrasistolic contraction of myocardium rats with postinfarction cardiosclerosis it was considerably oppressed, and rhythmoinitropic reaction of myocardium rats was comparable to reaction of intact myocardium at a diabetes induced streptozotocin. The combination postinfarction and diabetic influence is paradoxical promoted preservation postextrasistolic potentiation of myocardium rats.

Evaluation of the efficacy of granulocyte colony-stimulating factor for the treatment of experimental myocardial destruction in mice

We studied the effects of recombinant granulocytic CSF on heart remodeling in BALB/c mice after cryodestruction. Administration of granulocytic CSF was started 1 day after cryodestruction (subcutaneously, 10 μg/kg/day, for 4 days). As early as after the first injection, leukocytosis in the peripheral blood started to develop, leukocyte count peaked on days 4-6 and returned to normal on day 14. Treatment with granulocytic CSF significantly increased the content of progenitor cells in the bone marrow and led to rapid development of the inflammatory reaction and myocardium infiltration with mononuclear cells. Injections of granulocytic CSF did not reduce scar area, but provided significantly less pronounced heart hypertrophy, which attests to its better functional properties. By day 30 after cryodestruction, control animals and animals receiving granulocytic CSF exhibited similar morphological picture at the site of damage. Thus, our regimen of granulocytic CSF administration produced a mobilizing effect on bone marrow progenitor cells and postinfarction heart remodeling. Direct effects of granulocytic CSF on the heart have to be established for its use in the treatment of myocardial infarction.

[Experience in organization of joint actions of expert divisions during the accident at P.S. Podporozniy Sayano-Shushenskaya hydroelectric power station]

The authors illustrate positive experience in organization and coordination of joint actions of expert divisions of different sectors during the accident at P.S. Podporozniy Sayano-Shushenskaya hydroelectric power station in August 2009. Special emphasis is laid on the participation of experts of quick-reaction teams formed by territorial forensic medical bureaus, mobile and supporting forces from the adjacent regions.

[Effect of nonselective beta-adrenoblocker carvedilol on extrasystolic and postextrasystolic contractility in the rat myocardium after experimental infarction]

Features of the extrasystolic and postextrasystolic contractility of myocardium isolated from rats aged 4 months (group I, n = 30) and 12 months (group II, n = 30) after postinfarction remodeling of the heart (PIRH) and long-term treatment with carvedilol have been studied. Each age group included in 10 intact control animals, 10 animals with postinfarction cardiosclerosis (PICS), and 10 rats with PICS treated with carvedilol (2.1 mg/kg) during 28 days, beginning with the 45th day after coronary occlusion. The isometric contractility of myocardium was monitored at an electric stimulation frequency of 0.5 Hz. The extrasystolic effect was produced by an electric pulse applied within 0.2 - 5 s interval after the basic stimulation. It is established that the inotropic response of myocardium to the extrasystolic impulse exhibits age-dependent features both the intact rats and in the rats with PICS. The differences can be related to the age-dependent involvement of the ion-transport systems of sarcolemma and sarcoplasmic reticulum into the modulation of excitation--contractility coupling during PIRH. The long-term treatment with carvedilol led to restoration of the Ca(2+)-accumulation reserve of sarcoplasmic reticulum to the age-normal level in young animalsand decreased the risk of development of hemodynamically significant heart rate disturbances in old rats.

[Age-related features of intracellular calcium homeostasis in rat cardiomyocites in postinfarction heart remodeling]

Research results of features of an intracellular calcium homeostasis in 4 and 12-month's rat cardiomyocites at postinfarction cardiosclerosis are presented. It is shown that the myocardium of animals in the old rats group is more susceptible to extrasystolic impacts. In the pathology conditions additional extrasystolic influences also had the expressed age specificity of inotropic response. The data testifying to almost identical dynamics of postextrasystolic cycles of intact myocardium in animals of investigated age groups has been obtained. The different postextrasystolic potentiation in the remodeled myocardium in old and young rats testified to different of sarcoplasmic reticulum ability to accumulate additional calcium ions. The conclusion was made that the myocardium of animals in the old rats group has more chance for development of hemodynamic significant disturbance of cardiac rhythm as a consequence of age-related changes processes of the electromechanical coupling in cardiomyocites.

[Possible role of sarcoplasmatic reticulum in anti-arrhythmic effects of the class III agent amiodarone]

The study was designed to evaluate changes in functional activity of cardiomyocyte sarcoplasmic reticulum under effect of amiodarone (1 mM). It was shown that post-rest potentiation significantly increased after perfusion of cardiomyocytes with amiodarone or calcium (3 mM). The stimulatory action of amiodarone was more pronounced than that of calcium. Treatment with amiodarone solution containing high concentration of calcium had a lower potentiating effect compared with that of perfusion with either of them. Moreover, amiodarone in combination with calcium significantly extended the period of relaxation without affecting the contraction rate. It is concluded that amiodarone improves activity of sarcoplasmic reticulum.

[Features of lipid peroxidation in rats of different age with postinfarction cardiosclerosis]

Results of research of a state of lipid peroxidation (LP) system at rats by age of 4 and 12 months with postinfarction cardiosclerosis are presented in this work. It has been shown, that in the remote terms after an experimental myocardium infarct, age-dependent alteration of the LP and antioxidizing enzymes activity were observed. Also distinction in expressiveness of the LP processes in the intact animals in these age groups was revealed. Such age features probably cause various intensities of the LP and the state of antioxidant protection at postinfarction remodeling of heart.

[Comparative assessment of inotropic reaction of isolated myocardium of patients with ischemic and rheumatic heart disease after short-term periods of rest at the background of amiodarone]

We studied inotropic reaction of isolated myocardium of patients with heart failure induced by ischemic and rheumatic cardiac involvement after periods of rest at the background of amiodarone. The studies were carried out on muscular trabeculi separated from right atrial auricle during surgery. It was shown that inotropic reaction of insufficient myocardium could be of 2 types. In type I inotropic reaction first contraction after period of rest either exceeded basal contractions or remained at their level. Type 2 was characterized by significant lowering of amplitude of contractions relative to regular ones. Exposure of the myocardium to amiodarone (1 micro/L) led to significant potentiation of trabeculi contraction after periods of rest of muscles with type I reaction and did not affect response of muscles with type II reaction. These results allow to conclude that the state of calcium transporting systems of sarcoplasmic reticulum (SR) is different in ischemic and rheumatic heart failure and that realization of therapeutic effect of amiodarone depends on functional state of SR.

[Phospholipid composition of erythrocyte membranes under conditions of postmyocardial infarction cardiosclerosis]

Changes in phospholipid composition of the erythrocyte membranes have been studied in experimental postmyocardial infarction cardiosclerosis. Erythrocyte membranes from animals with cardiosclerosis formed after experimantal occlusions of coronary arteries were characterized by significant decrease of a minor phospholipid, phosphatydylinositol (by more than 40%) and the increase of the major phospholipid, phosphatydylethanolamine. There was high content of lipid peroxidation products, malondialdehyde and conjugated dienes and the decrease in the activity of antioxidant enzymes, catalase and superoxide dismutase in blood serum of these animals. We have concluded the formation of postmyocardial infarction cardiosclerosis is accompanied by the increase of free radical reactions. This causes changes in phospholipid composition of cell membranes and the decrease of compensatory capacities of the enzymatic antioxidant system. These changes form a metabolic background, [corrected] which can influence cardiac remodelling properties.

[Activity of lipid peroxidation and functional state of the myocardium in remodeling of rat heart after experimental myocardial infarction]

It was shown in experiments on Wistar rats that the processes of postinfarction remodeling of the heart in animals that survived myocardial infarction were characterized by lowering of excitability of cardiac muscle, impairment of ability of sarcoplasmic reticulum to accumulate calcium ions. High level of content of lipid peroxidation products both in blood serum and myocardial tissue, and lowering of activity of antioxidant enzymes were also noted. A conclusion was made that high level of lipid peroxidation, lowering of defense properties of endogenous antioxidants and impairment of myocardial contractile function induced by myocardial infarction were sustained minimally for subsequent 45 days. This could serve as a factor, capable to significantly affect the process of postinfarction remodeling and development of heart failure.

[Acute and chronic amiodarone effects on the dynamics of force-interval relationship in rat papillary muscle]

Effects of acute and chronic amiodarone treatment on the force-interval relationship were investigated in rat papillary muscle. It was found that both acute and chronic amiodarone treatment decreased the amplitude of extrasystoles. At the same time, only short-term administgration of amiodarone increased postextrasystols and post-rest potentiations of twitch force in rat myocardium. It is concluded that the acute and chronic amiodarone treatment suppress the excitability of cardiomyocytes, but only the chronic treatment increases the effective refractory period. The results suggest that the acute administration of amiodarone can influence the intracellular calcium homeostasis.

Metabolic alterations in rat myocardium in experimental acute atrial fibrillation

Experimental atrial fibrillation in intact rats significantly decreased the content of catecholamines in atrial adrenergic fibers and phosphorylase activity, which attests to enhanced glycogen consumption in the heart. These changes were specific of the fibrillating myocardium and atria, but were absent in the ventricles. Induced atrial fibrillation did not modify activities of SDH and monoamine oxidase in cardiac subdivisions. It was hypothesized that increased energy requirements in the atria during myocardial fibrillation led to activation of anaerobic metabolism.

[Changes in the binding properties of albumin in patients with myocardial infarction]

The purpose of the study was to measure the levels of albumin and to evaluate its binding properties in patients with acute large-focal myocardial infarction (AMI) hospitalized within the first 24 hours of AMI onset. Two groups were formed: group one--41AMI patients without cardiogenic shock (CS) and group two--15 patients with AMI complicated by true CS. Blood samples were taken from an ulnar vein on the first, second, third, fifth, seventh, and fourteenth day after AMI onset. The properties of binding albumin centers were determined using fluorescent method (K-35 probe). Total albumin concentration (TAC), effective albumin concentration (EAC), and albumin binding reserve (ABR) were determined. The results were presented as M +/- m. A significant increase in TAC on the fifth day (from 43 +/- 1 to 40 +/- 1 g/l) and EAC on the second, third, fifth, and seventh days (from 36 +/- 1 to 32 +/- 1 g/l with the minimal level on the fifth day), and in ABR on the second day (from 83.3 +/- 1.3 to 78.8 +/- 8%) were registered in group one. TAC returned to the normal level on the seventh day, EAC did not become normal until the fourteenth day, while ABR did not normalize within the period of two weeks. Eleven patients in group two died (hospital CS-associated mortality was 73.3%). TAC and EAC in discharged patients were 43.4 +/- 0.9 g/l and 35.8 +/- 0.8 g/l, respectively, while these parameters in the deceased were 35.5 +/- 1.7 g/l (p < 0.0001) and 27.3 +/- 1.7 g/l (p < 0.0001), respectively. CS developed in 70% of cases (seven out of ten patients) in whom TAC was less than 36 g/l vs. 17.4% of cases (eight out of 46) with a TAC of 36 g/l or more (p = 0.0013). When EAC was less than 30 g/l CS developed in 72.7% of cases (eight out eleven patients) vs. 15.6% of cases (seven out of 45) with an EAC of 30 g/l or more (p = 0.0003). Six out of ten patients (60%) with a TAC of less than 36 g/l died. Lethal outcome also occurred in five cases out of 46 or 10.9% with a TAL of 36 g/l or more (p = 0.0008). Seven out of eleven or 63.6% patients with an EAC of less than 30 g/l died. Four out of 45 patients (8.9%) with an EAC of 30 g/l or more died (p = 0.0001). Thus, the study found that a low (less than 36 g/l) TAC and EAC (less than 30 g/l) during the first 24 hours of AMI was associated with a significantly higher frequency of true CS and with a significantly higher hospital lethality. Determining albumin parameters during the first 24 hours of AMI will be useful in distinguishing a group of patients with a high risk of lethal outcome, which will make it possible to begin early aggressive therapy directed towards limiting myocardial necrosis.

A Simple Method for Isolation of Cardiomyocytes from Adult Rat Heart

A simple, economic, and sparing method for isolation of cardiomyocytes from adult rat heart is proposed. Ultrastructure of cardiomyocytes from suspension of freshly isolated cells was studied by light and transmission electron microscopy. The isolated cardiomyocytes were viable, had characteristic shape and size, and retained their normal structure.

Initiation of stress protein synthesis in the myocardium of coronary patients

We studied myocardial biopsy specimens from the right atrium of cardiological patients with different degree of cardiac ischemia obtained during surgery. No inducible HSP70 stress proteins were detected in atrial cardiomyocytes of patients with the WPW syndrome without signs of ischemic injuries of the heart. These proteins were detected in the myocardium of coronary patients. Their expression was more intense in patients with coronary disease paralleled by the development of myocardial dyskinesia. Two-dimensional electrophoresis showed only acid HSP70 but no alkaline isoforms in coronary patients even with pronounced dyskinesia. Presumably, alkaline HSP70 isoforms are present in the myocardium directly involved in the dyskinesia zone.

In vitro formation of mesenchymal bone marrow islets

We studied the formation of mesenchymal islets in the culture of bone marrow cells in vitro. Islet-like structures detected on day 6 of culturing contained a central epithelioid cell (differing from macrophages and fibroblasts) surrounded with round mesenchymal cells. The number of mesenchymal islets increased on days 12-14 of culturing, but decreased to zero by the 24th day. They appeared not only as individual structures, but also entered the composition of colonies and formed assemblies with surrounding cells of different maturity. Our results show that mesenchymal islets serve as structural and functional units of mesenchymopoiesis.

Inotropic Response of the Myocardium in Rats with Postinfarction Cardiosclerosis Exposed to Extrasystolic Treatment

The inotropic response of the myocardium to extrasystolic treatment was studied on isolated perfused papillary muscles from rats with postinfarction cardiosclerosis. The development of postinfarction cardiosclerosis was accompanied by a decrease in myocardial excitability. The amplitude of extrasystolic contractions in the remodeled myocardium far surpassed the control. However, the amplitude of postextrasystolic contraction did not surpass that in normal contraction-relaxation cycle. Our results suggest that the ability of the sarcoplasmic reticulum in cardiomyocytes to accumulate Ca2+ is impaired during postinfarction remodeling.

[Inotropic reactions of myocardium of patients with ischemic heart disease and rats during use of amiodarone]

AIM

To study effect of amiodarone on inotropic reactions of myocardium of patients with ischemic heart disease and rats.

METHODS AND RESULTS

Excitability of rat myocardium has been found to be higher than that of myocardium of patients. Sarcoplasmic reticulum of myocardium of rats has greater functional reserve, therefore rat muscle preparations respond to extrasystolic stimuli with postextrasystolic potentiation. Perfusion with a solution containing amiodarone caused diminution of amplitude of extrasystolic response of muscular strips both from rats and patients. Amiodarone augmented ability of sarcoplasmic reticulum to accumulate Ca ions as it prevented decrease of postextrasystolic contraction of human myocardium and brought about postextrasystolic potentiation of muscular strips of rat myocardium.

CONCLUSION

Amiodarone affected intracellular homeostasis of calcium ions in cardiomyocytes of both rats and patients. Amiodarone lowered myocardial excitability and facilitated ability of cardiomyocyte sarcoplasmic reticulum to accumulate calcium ions.

[Potential of bone marrow mesenchymal stem cells for the treatment of diseases associated with damage of cardiac tissue]

Ability of mononuclear and adhesive cells to form differentiated elements of various tissues and organs in tissue culture in vitro has been studied in experiments on CBA mice. It has been established that adhesion mesenchymal stem cells are present in bone marrow. These cells are able to generate muscular, nervous, endothelioid, epithelioid, reticular, fibroblastoid, chondrogenic, osteogenic, and other types of cells. Mesenchymal islets have been frequently found both as parts of colonies and as independent units. Potential developmental flexibility of mesenchymal cells allows to suppose their high efficacy in pathogenetic cell therapy of heart diseases when besides damaged muscular elements vascular and nervous elements should be also restored. Mononuclear cells have not demonstrated this ability. They formed mainly monocyte-macrophagal and lymphoid cells.

Intraoperative preparation of the radial artery for coronary artery bypass grafting

In coronary surgery, the problem of pharmacological prevention of vasospasm of the bypass from the radial artery (RA) remains unsolved until now. In view of this circumstance the authors propose a method for the use of aminazine (chlorpromazine), a phenothiazine series inhibitor of calmodulin, for prevention of vasospasm of auto-arterial bypasses from the RA at coronary artery bypass grafting (CABG). An analysis was made of the results of 30 CABGs using the RA conduit. The operations were performed at the Department of Cardiovascular Surgery, SI Research Institute of Cardiology, TSC, SB RAMS. The experimental data presented herein demonstrate that intraoperative treatment of the exposed RA by aminazine solution in a concentration of 10-6 M/L may prevent spasm of the bypass from the RA for a long time. Control bypassgraphy carried out over the first postoperative week has revealed that all the bypasses from the RA are functionally competent. So, the method proposed allows a reliable, effective and prevention of perioperative spasm of auto-arterial bypasses from the RA at CABG.

[Effect of calcium antagonists verapamil and amlodipine on the risk of development of atrial fibrillation after coronary artery bypass grafting]

AIM

To assess effect of calcium antagonists amlodipine and verapamil on the risk of development of atrial fibrillation after coronary artery bypass surgery.

MATERIAL

Of 74 patients subjected to mammary artery and venous coronary bypass grafting with the use of cardiopulmonary bypass 19 received amlodipine and 21 - verapamil.

RESULTS AND CONCLUSION

Attacks of atrial fibrillation during 24 hour ECG monitoring were registered in 22.9% of patients mostly on days 2 and 3 after surgery. In verapamil treated patients atrial fibrillation occurred 1.5-2 times more often than in amlodipine treated patients or in patients receiving no calcium antagonists. This could possibly be explained by pronounced slowing of atrio-ventricular conduction by verapamil at the background of postoperative general "irritation" of the atrial myocardium.

[Study of stability of lactate dehydrogenase isoenzymes in leucocytes of elderly people]

In this paper was investigated stability of isoenzymes of lactatdehydrogenase (LDH) of leukocytes of peripheral blood of persons at the age of 20 years (n=10) and more than 65 years (n=8). Extraction of the leukocytes was conducted by centrifugation of human blood on a double gradient of density. Leukocytes were destroyed by hypotonic shock in combination with vibration. Separation of LDH isoenzymes from destroyed leukocytes was conducted by the method of native electrophores. The revealing of activity of LDH isoenzymes was conducted by the method of restoration of nitroblue tetrasolium. Isoenzymes stability was evaluated according to alteration of activity after the incubation of destroyed leukocytes with urea in various concentrations (1M, 2M and 3M). Was shown the presence of three isoenzymes of LDG (LDH-1, LDH-2, LDH-3) in human leukocytes. As the age-dependent alteration of activity of isoenzymes of lactatdehydrogenase in human leukocytes was shown. It can be caused by age-related changes of physico-chemical properties of leukocytes' membranes and/or isoenzymes stability. Stability of LDH-3 was decreased with the age. Observed decrease of LDH-3 stability can be caused by age-related modification of M-subunits of the studied isoenzymes.

[Effect of amiodarone on the extrasystolic and post-extrasystolic contractions of the isolated myocardium of rats and of patients with chronic ischemic heart disease]

Peculiarities in the extrasystolic and post-extrasystolic contractility of the isolated myocardium of patients suffering from chronic ischemic heart disease (IHD), in comparison to that of intact rats, were studied in the presence of the antiarrhythmic drug amiodarone. The contractility was measured in an isometric mode at an electric stimulation frequency of 0.5 Hz, a temperature of 37 degrees C, and a perfusion rate of 10 ml/min. The extrasystolic action was produced by additional electric pulses generated 25 sec after the base stimulation signal. Amiodarone (1 microgram/ml) reduced the inotropic response of intact rat myocardium to the extrasystolic action, but increased the post-extrasystolic contractility. In the myocardium of IHD patients, the drug also suppressed manifestations of the spontaneous abnormal contractility, while not decreasing the inotropic response to the extrasystolic action. An increase in the post-extrasystolic contractility reached on the average 24% (against 6% in the control). The effect of amiodarone on the post-extrasystolic contractility can be related to a change in the functional state of sarcoplasmic reticulum (SR) and in the content of deposited Ca2+ ions. SR is an important factor of intracellular homeostasis of cardiomyocytes during IHD and can probably influence the antiarrhythmic efficacy of amidarone in IHD patients.